RFR(XS) : 8021120 : TieredCompilation can be enabled even if TIERED is undefined

[Vladimir Kozlov]

On 7/24/13 10:16 PM, David Holmes wrote:
> On 25/07/2013 12:31 AM, Vladimir Kozlov wrote:
>> On 7/24/13 4:29 AM, David Holmes wrote:
>>> On 24/07/2013 9:12 AM, Vladimir Kozlov wrote:
>>>> David,
>>>>
>>>> We can't use UNSUPPORTED_OPTION because of the message it produces: "is
>>>> disabled in this release." We need: "is not supported in this VM."
>>>
>>> Do the exact words really matter? If it is disabled it is not supported.
>>>
>>> But the patch issues no warning it simply ignores what the user has
>>> asked for. I prefer it when people get told they are
>>> asking for something they can't have.
>>
>> Last version Igor sent has warning:
>>
>> http://cr.openjdk.java.net/~iignatyev/8021120/webrev.01/
>
> I never saw that one as it only went to hotspot-compiler-dev. (The other alias should not be cc'd and I've dropped it -
> which means I won't see any replies unless explicitly cc'd :) ).
>
> I still don't see that the UNSUPPORTED_OPTION wording should be an issue here. If you really think it is then rework the
> macro to allow the main text to be passed as well. But this seems a non-issue to me. After all who are we targetting
> with this?

Embedded VM :) Embedded Server VM does not support Tiered (is not built with it).

Anyway, I looked and currently UNSUPPORTED_OPTION is used only in 2 places (I thought a lot more). And in both places it 
really mean "not supported":

#ifdef _ALLBSD_SOURCE  // UseLargePages is not yet supported on BSD.
   UNSUPPORTED_OPTION(UseLargePages, "-XX:+UseLargePages");
#endif

#if INCLUDE_ALL_GCS
   #if (defined JAVASE_EMBEDDED || defined ARM)
     UNSUPPORTED_OPTION(UseG1GC, "G1 GC");
   #endif
#endif

So I agree with you now that we can change message in UNSUPPORTED_OPTION to

warning(description " is not supported in this VM.");

Igor, please, do as David suggested, modify message and use UNSUPPORTED_OPTION.

Thanks,
Vladimir

>
> David
> -----
>
>> Vladimir
>>
>>>
>>> David
>>>
>>>> Thanks,
>>>> Vladimir
>>>>
>>>> On 7/23/13 4:04 PM, David Holmes wrote:
>>>>> Hi Igor,
>>>>>
>>>>> On 23/07/2013 10:38 PM, Igor Ignatyev wrote:
>>>>>> Hi all,
>>>>>>
>>>>>> Please review patch.
>>>>>>
>>>>>> Problem:
>>>>>> If 'COMPILER2' is defined, it will be possible to enable
>>>>>> 'TieredCompilation' even if 'TIERED' is undefined. But such VM will
>>>>>> raise error at 'compilationPolicy_init'
>>>>>>
>>>>>> Fix:
>>>>>> Forcibly set 'TieredCompilation' in false, if 'TIERED' is undefined.
>>>>>
>>>>> If you use UNSUPPORTED_OPTION it will issue a warning and force it to
>>>>> false.
>>>>>
>>>>> David
>>>>> -----
>>>>>
>>>>>> webrev: http://cr.openjdk.java.net/~iignatyev/8021120/webrev.00/
>>>>>> jbs: https://jbs.oracle.com/bugs/browse/JDK-8021120
>>>>>> testing: jprt, 'java -version' on different VM (including embedded
>>>>>> client, server, minimal)